Impaired post-sleep apnea autonomic arousals in patients with drug-resistant epilepsy.

OBJECTIVE: Sudden and unexpected deaths in epilepsy (SUDEP) pathophysiology may involve an interaction between respiratory dysfunction and sleep/wake state regulation. We investigated whether patients with epilepsy exhibit impaired sleep apnea-related arousals. METHODS: Patients with drug-resistant (N = 20) or drug-sensitive (N = 20) epilepsy and obstructive sleep apnea, as well as patients with sleep apnea but without epilepsy (controls, N = 20) were included. We explored (1) the respiratory arousal threshold based on nadir oxygen saturation, apnea-hypopnea index, and fraction of hypopnea among respiratory events; (2) the cardiac autonomic response to apnea/hypopnea quantified as percentages of changes from the baseline in RR intervals (RRI), high (HF) and low (LF) frequency powers, and LF/HF. RESULTS: The respiratory arousal threshold did not differ between groups. At arousal onset, RRI decreased (-9.42%) and LF power (179%) and LF/HF ratio (190%) increased. This was followed by an increase in HF power (118%), p < 0.05. The RRI decrease was lower in drug-resistant (-7.40%) than in drug-sensitive patients (-9.94%) and controls (-10.91%), p < 0.05. LF and HF power increases were higher in drug-resistant (188%/126%) than in drug-sensitive patients (172%/126%) and controls (177%/115%), p < 0.05. CONCLUSIONS: Cardiac reactivity following sleep apnea is impaired in drug-resistant epilepsy. SIGNIFICANCE: This autonomic dysfunction might contribute to SUDEP pathophysiology.

Aspects clinico-neurophysiologiques des troubles du sommeil dans une population d'adultes jeunes entre 18-35 ans / Clinical-neurophysiological aspects of sleep disorders in a population of young adults aged 18-35 years

Contexte et objectifs : L'accès aux tests neurophysiologiques pour le diagnostic des Troubles du Sommeil (TS) est très limité dans les pays d'Afrique subsaharienne. La présente étude avait pour objectif de déterminer les caractéristiques épidémiologiques, cliniques et neurophysiologiques des (TS) dans un groupe de jeunes adultes. Méthodes : Il s'est agi d'une étude descriptive d'une série de cas, réalisée au centre de Médecine du sommeil et des maladies respiratoires de l'hôpital de la Croix-Rousse de Lyon du 1er janvier au 31 mars 2019. Les patients hospitalisés pendant cette période pour l'exploration d'un (TS) ont été sélectionnés. Etaient éligibles ceux dont l'âge était compris entre 18 et 35 ans, des deux sexes, ayant renseigné un questionnaire et ayant bénéficié au minimum d'une polysomnographie (PSG). Résultats : Quatre-vingt-onze patients étaient examinés. Les femmes étaient les plus affectées (59,3 %). Leur âge moyen était de 26,6 ± 5 ans. La PSG a incriminé le Syndrome d'Apnée Hypopnée Obstructive du sommeil (SAHOS) comme étiologie principale (66 %). Pour les patients sans SAHOS, 38,7 % avaient une PSG normale et la PSG avec d'autres tests de sommeil ont objectivé, pour le reste (61,3 %), d'autres types de (TS). La dépression (50,7 %) et la fatigue chronique (84,6 %) étaient très fréquentes. L'indice d'efficacité du sommeil était faible pour 70 % des patients avec SAHOS. Il y avait un déséquilibre de la durée des stades du sommeil, augmentée pour le sommeil lent léger et diminuée pour le sommeil lent profond dans la population avec SAHOS, tandis que la durée du sommeil paradoxal chez ceux sans SAHOS était augmentée. Conclusion Le SAHOS est fréquent dans cette formation hospitalière, avec des répercussions significatives à type de dépression et de fatigue chronique. Il est important que des mesures rendant accessible l'usage des tests d'exploration du sommeil particulièrement en Afrique au sud du Sahara, soient mises en place pour diagnostiquer ces troubles

Context and objective. Access to neurophysiological tests for diagnostic of sleep disorders (SD) is very limited in Sub-Saharan Africa countries. The objective was to determine the epidemiological, clinical and neurophysiological characteristics of SD in a young adult group. Methods. This was a descriptive serial cases study carried out at the Sleep Medicine and Respiratory Diseases Center of the CroixRousse hospital of Lyon between January 1st and March 31th, 2019. Patients hospitalized during this period with tests for SD were selected. Eligible were those aged between 18 and 35 years, both sexes, who completed a questionnaire and who received at least a polysomnography (PSG). Results. Ninety-one patients were involved. Women remained the most affected (59.3%). Mean age was 26.6±5 years. PSG incriminated obstructive sleep apnea (OSA) syndrome as the primary etiology (66%). For patients without OSA, 38.7% had normal PSG. For the remaining 61.3% of patients, other types of SD were found using PSG with various sleep tests. Depression (50.7%) was an important comorbidity, and chronic fatigue (84.6%) was the most frequent complaint. Sleep efficiency index was low for 70% of sleep apnea patients. There was an imbalance in the duration of sleep stages, with an increase in light slow-wave sleep in the OSA population and a decrease in their deep slow-wave sleep, while REM sleep duration in patients without OSA was increased. Conclusion: OSA was the primary etiology in our study, with significant repercussions like depression and chronic fatigue. Public health measures such as increasing access to the use of sleep exploration tests, especially in subSaharan Africa, should be put in place for the diagnosis of these sleep disorders and their consequences

Revisiting the maintenance of wakefulness test: from intra-/inter-scorer agreement to normative values in patients treated for obstructive sleep apnea.

The Maintenance of Wakefulness Test is widely used to objectively assess sleepiness and make safety-related decisions, but its interpretation is subjective and normative values remain debated. Our work aimed to determine normative thresholds in non-subjectively sleepy patients with well-treated obstructive sleep apnea, and to assess intra- and inter-scorer variability. We included maintenance of wakefulness tests of 141 consecutive patients with treated obstructive sleep apnea (90% men, mean (SD) age 47.5 (9.2) years, mean (SD) pre-treatment apnea-hypopnea index of 43.8 (20.3) events/h). Sleep onset latencies were independently scored by two experts. Discordant scorings were reviewed to reach a consensus and half of the cohort was double-scored by each scorer. Intra- and inter-scorer variability was assessed using Cohen's kappa for 40, 33, and 19 min mean sleep latency thresholds. Consensual mean sleep latencies were compared between four groups according to subjective sleepiness (Epworth Sleepiness Scale score < versus ≥11) and residual apnea-hypopnea index (< versus ≥15 events/h). In well-treated non-sleepy patients (n = 76), the consensual mean (SD) sleep latency was 38.4 (4.2) min (lower normal limit [mean - 2SD] = 30 min), and 80% of them did not fall asleep. Intra-scorer agreement on mean sleep latency was high but inter-scorer was only fair (Cohen's kappa 0.54 for 33-min threshold, 0.27 for 19-min threshold), resulting in changes in latency category in 4%-12% of patients. A higher sleepiness score but not the residual apnea-hypopnea index was significantly associated with a lower mean sleep latency. Our findings suggest a higher than usually accepted normative threshold (30 min) in this context and emphasise the need for more reproducible scoring approaches.

Unveiled central hypoventilation after tracheotomy in anti-IgLON5 disease: a case report.

Anti-IgLON5 disease is a recently described entity that has been associated with neurological symptoms and sleep disturbances including sleep breathing disorders. Sleep stridor as well as obstructive and less often central sleep apnea have been reported but rarely needing ventilation on tracheotomy. We report the case of a patient in whom obstructive sleep apnea with secondary development of dysphagia and recurrent aspiration pneumonia led to the diagnosis of anti-IgLON 5 disease. Acute respiratory failure due to laryngospasm required intubation and eventually tracheotomy. Yet hypoventilation persisted, and polysomnography demonstrated central sleep apnea alternating with sleep-related tachypnea. Nocturnal ventilation was thus reintroduced. The association of obstructive sleep apnea with dysphagia is a potential red flag for anti-IgLON5 disease, which remains an overlooked diagnosis. Breathing disorders can be complex in this context, with a mixed obstructive and central pattern whose central component can be unveiled after tracheotomy. This highlights the importance of closely monitoring sleep and respiration even after tracheotomy. CITATION: Tankéré P, Le Cam P, Folliet L, et al. Unveiled central hypoventilation after tracheotomy in anti-IgLON5 disease: a case report. J Clin Sleep Med. 2023;19(9):1701-1704.

Epidemiology of Bovine Hemorrhagic Bowel Syndrome in Belgium and The Netherlands.

Hemorrhagic bowel syndrome (HBS) is a poorly understood, sporadic and often fatal disease in cattle. Although, HBS is considered an important disease in dairy cattle, epidemiological data is largely lacking. This study describes the epidemiology of HBS in Belgium and the Netherlands, based on necropsy records from 2009 to 2022, and reports characteristics from 27 cows and 35 dairy operations with HBS, gathered through a survey. The annual incidence of HBS has a significantly increasing trend both at cow and herd level, with incidence above 3.2% in necropsied mature dairy cattle in the most recent years. Estimated herd-level incidence in the Netherlands was double the estimated incidence in Belgium, which might be explained by higher herd size in the Netherlands. Occurrence of HBS was most prevalent in fall, being 40.1% higher than the average of the other seasons. In 35 Flemish (Belgian) surveyed dairy herds with HBS, manifestation of HBS was mostly as solitary cases, and if multiple cases occurred, the time interval was highly variable. In addition, the majority of cows with HBS (61.1%; 16/26) were in more than 100 days lactation. In conclusion, HBS is an important and possibly emerging disease in dairy cattle in Belgium and the Netherlands.

Acer pseudoplatanus: A Potential Risk of Poisoning for Several Herbivore Species.

Acer pseudoplatanus is a worldwide-distributed tree which contains toxins, among them hypoglycin A (HGA). This toxin is known to be responsible for poisoning in various species, including humans, equids, Père David's deer and two-humped camels. We hypothesized that any herbivore pasturing with A. pseudoplatanus in their vicinity may be at risk for HGA poisoning. To test this hypothesis, we surveyed the HGA exposure from A. pseudoplatanus in species not yet described as being at risk. Animals in zoological parks were the major focus, as they are at high probability to be exposed to A. pseudoplatanus in enclosures. We also searched for a toxic metabolite of HGA (i.e., methylenecyclopropylacetyl-carnitine; MCPA-carnitine) in blood and an alteration of the acylcarnitines profile in HGA-positive animals to document the potential risk of declaring clinical signs. We describe for the first instance cases of HGA poisoning in Bovidae. Two gnus (Connochaetes taurinus taurinus) exposed to A. pseudoplatanus in their enclosure presented severe clinical signs, serum HGA and MCPA-carnitine and a marked modification of the acylcarnitines profile. In this study, even though all herbivores were exposed to A. pseudoplatanus, proximal fermenters species seemed less susceptible to HGA poisoning. Therefore, a ruminal transformation of HGA is hypothesized. Additionally, we suggest a gradual alteration of the fatty acid metabolism in case of HGA poisoning and thus the existence of subclinical cases.

Nocturnal Hypoxemia Rather Than Obstructive Sleep Apnea Is Associated With Decreased Red Blood Cell Deformability and Enhanced Hemolysis in Patients With Sickle Cell Disease.

Background: Although obstructive sleep apnea (OSA) could act as a modulator of clinical severity in sickle cell disease (SCD), few studies focused on the associations between the two diseases. Research Question: The aims of this study were: (1) to explore the associations between OSA, nocturnal oxyhemoglobin saturation (SpO2) and the history of several acute/chronic complications, (2) to investigate the impact of OSA and nocturnal SpO2 on several biomarkers (hematological, blood rheological, and coagulation) in patients with SCD. Study Design and Methods: Forty-three homozygous SCD patients underwent a complete polysomnography recording followed by blood sampling. Results: The proportion of patients suffering from nocturnal hypoxemia did not differ between those with and those without OSA. No association between OSA and clinical severity was found. Nocturnal hypoxemia was associated with a higher proportion of patients with hemolytic complications (glomerulopathy, leg ulcer, priapism, or pulmonary hypertension). In addition, nocturnal hypoxemia was accompanied by a decrease in RBC deformability, enhanced hemolysis and more severe anemia. Interpretation: Nocturnal hypoxemia in SCD patients could be responsible for changes in RBC deformability resulting in enhanced hemolysis leading to the development of complications such as leg ulcers, priapism, pulmonary hypertension or glomerulopathy. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03753854.

Microsleep versus Sleep Onset Latency during Maintenance Wakefulness Tests: Which One Is the Best Marker of Sleepiness?

The interpretation of the Maintenance Wakefulness Test (MWT) relies on sleep onset detection. However, microsleeps (MSs), i.e., brief periods of sleep intrusion during wakefulness, may occur before sleep onset. We assessed the prevalence of MSs during the MWT and their contribution to the diagnosis of residual sleepiness in patients treated for obstructive sleep apnea (OSA) or hypersomnia. The MWT of 98 patients (89 OSA, 82.6% male) were analyzed for MS scoring. Polysomnography parameters and clinical data were collected. The diagnostic value for detecting sleepiness (Epworth Sleepiness Scale > 10) of sleep onset latency (SOL) and of the first MS latency (MSL) was assessed by the area under the receiver operating characteristic (ROC) curve (AUC, 95% CI). At least one MS was observed in 62.2% of patients. MSL was positively correlated with SOL (r = 0.72, p < 0.0001) but not with subjective scales, clinical variables, or polysomnography parameters. The use of SOL or MSL did not influence the diagnostic performance of the MWT for subjective sleepiness assessment (AUC = 0.66 95% CI (0.56, 0.77) versus 0.63 95% CI (0.51, 0.74)). MSs are frequent during MWTs performed in patients treated for sleep disorders, even in the absence of subjective sleepiness, and may represent physiological markers of the wake-to-sleep transition.

Grazing Mares on Pasture with Sycamore Maples: A Potential Threat to Suckling Foals and Food Safety through Milk Contamination.

Equine atypical myopathy (AM) is seasonal intoxication resulting from the ingestion of seeds and seedlings of the sycamore maple (Acer pseudoplatanus) that contain toxins, among them, hypoglycin A (HGA). Literature mentions several cases of AM among gravid mares and in unweaned foals. The objective of this study was to determine whether HGA and/or its metabolite are present in milk from grazing mares exposed to sycamore maple trees as confirmed by detection of HGA and its metabolite in their blood. Four mare/foal couples were included in the study. Both HGA and its metabolite were detectable in all but one of the milk samples. To our knowledge, this is the first study describing transfer of HGA to the milk. This unprecedented observation could partially explain cases of unweaned foals suffering from AM. However, a transplacental transfer of the toxin cannot be excluded for newborn foals. Besides being a source of contamination for offspring, milk contamination by toxins from fruits of trees of the Sapindaceae family might constitute a potential risk for food safety regarding other species' raw milk or dairy products.

Laboratory Diagnosis of Bovine Abortions Caused by Non-Maintenance Pathogenic Leptospira spp.: Necropsy, Serology and Molecular Study Out of a Belgian Experience.

: Bovine leptospirosis is a bacterial zoonotic disease caused by pathogenic Leptospira spp.. The pathology and epidemiology of this infection are influenced by the numerous existing serovars and their adaptation to specific hosts. Infections by host-maintained serovars such as Hardjo are well documented, unlike those from the incidental ones. In July 2014, an emerging phenomenon of an increased incidence of icteric abortions associated with leptospiral infection occurred in southern Belgium. First-line serological analyses targeting cattle-adapted serovars failed at initial diagnosis. This study provides a comprehensive description of laboratory findings-at the level of necropsy, serology and molecular diagnosis-regarding icteric and non-icteric abortions (n = 116) recorded during this time (years 2014-2015) and associated with incidental infection by serovars such as Grippotyphosa, Australis and Icterohaemorrhagiae. Based on these tests, a diagnostic pathway is proposed for these types of infection in cattle to establish an affordable but accurate diagnosis in the future. These investigations add insights into the understanding of the pathogenesis of bovine leptospirosis associated with serovars classically described as non-maintenance.

Complete Genome Sequence of Bovine Polyomavirus Type 1 from Aborted Cattle, Isolated in Belgium in 2014.

The complete and fully annotated genome sequence of a bovine polyomavirus type 1 (BPyV/BEL/1/2014) from aborted cattle was assembled from a metagenomics data set. The 4,697-bp circular dsDNA genome contains 6 protein-coding genes. Bovine polyomavirus is unlikely to be causally related to the abortion cases.

Absence of airway secretion accumulation predicts tolerance of noninvasive ventilation in subjects with amyotrophic lateral sclerosis.

OBJECTIVE: To assess factors that predict good tolerance of noninvasive ventilation (NIV), in order to improve survival and quality of life in subjects with amyotrophic lateral sclerosis. METHODS: We conducted a prospective study in subjects with amyotrophic lateral sclerosis and requiring NIV. The primary end point was NIV tolerance at 1 month. Subjects, several of whom failed to complete the study, were classified as "tolerant" or "poorly tolerant," according to the number of hours of NIV use (more or less than 4 h per night, respectively). RESULTS: Eighty-one subjects, 73 of whom also attended the 1-month follow-up visit, participated over 34 months. NIV tolerance after the first day of utilization predicted tolerance at 1 month (77.6% and 75.3% of subjects, respectively). Multivariate analysis disclosed 3 factors predicting good NIV tolerance: absence of airway secretions accumulation prior to NIV onset (odds ratio 11.5); normal bulbar function at initiation of NIV (odds ratio 8.5); and older age (weakly significant, odds ratio 1.1). CONCLUSION: Our study reveals 3 factors that are predictive of good NIV tolerance, in particular the absence of airway secretion accumulation, which should prompt NIV initiation before its appearance.

Motor and respiratory heterogeneity in Duchenne patients: implication for clinical trials.

AIMS: Our objective was to clarify the clinical heterogeneity in Duchenne muscular dystrophy (DMD). METHODS: The French dystrophinopathy database provided clinical, histochemical and molecular data of 278 DMD patients (mean longitudinal follow-up: 14.2 years). Diagnosis was based on mutation identification in the DMD gene. Three groups were defined according to the age at ambulation loss: before 8 years (group A); between 8 and 11 years (group B); between 11 and 16 years (group C). RESULTS: Motor and respiratory declines were statistically different between the three groups, as opposed to heart involvement. When acquired, running ability was lost at the mean age of 5.41 (group A), 7.11 (group B), 9.19 (group C) years; climbing stairs ability at 6.24 (group A), 7.99 (group B), 10,42 (group C) years, and ambulation at 7.10 (group A), 9.25 (group B), 12.01 (group C) years. Pulmonary growth stopped at 10.26 (group A), 12.45 (group B), 14.58 (group C) years. Then, forced vital capacity decreased at the rate of 8.83 (group A), 7.52 (group B), 6.03 (group C) percent per year. Phenotypic variability did not rely on specific mutational spectrum. CONCLUSION: Beside the most common form of DMD (group B), we provide detailed description on two extreme clinical subgroups: a severe one (group A) characterized by early severe motor and respiratory decline and a milder subgroup (group C). Compared to group B or C, four to six times fewer patients from group A are needed to detect the same decrease in disease progression in a clinical trial.

The short-term effects of intermittent positive pressure breathing treatments on ventilation in patients with neuromuscular disease.

BACKGROUND: The effects of intermittent positive-pressure breathing (IPPB) and abdominal belt on regional lung ventilation in neuromuscular patients are unknown. We conducted a prospective physiologic short-term study in stable neuromuscular patients to determine the effects of IPBB, with and without abdominal belt, on regional lung ventilation. METHODS: IPPB was performed as 30 consecutive deep breaths up to 30 cm H(2)O face-mask pressure each: 10 in supine position, 10 in left-lateral position, and 10 in right-lateral position. Each patient received IPPB sessions with and without an abdominal belt, in a random order, at one-day intervals. Patients were then followed-up to 3 hours after IPPB. Lung ventilation was measured via electrical-impedance tomography (tidal volume via electrical-impedance tomography [electrical-impedance V(T)], which is reported in arbitrary units) in 4 lung quadrants. Baseline V(T) and exhaled V(T) after each deep breath were also measured. The primary outcome was maintenance of regional ventilation after 3 hours. RESULTS: Global electrical-impedance V(T) remained significantly higher than at baseline as long as 3 hours after the IPPB sessions. Global and regional electrical-impedance V(T) at the end of the 3-hour study period was significantly higher with the abdominal belt in place. Regional ventilation did not change significantly. With IPPB in the supine position, electrical-impedance V(T) was significantly greater in the anterior than the posterior lung regions (P < .001). With IPPB in supine position, median and interquartile range V(T) values increased from 0.25 L (0.20-0.30) to the exhaled V(T) of 1.50 L (1.08-1.96) (P < .001). There were no differences in regional ventilation. CONCLUSIONS: In patients with neuromuscular disease, supine IPPB treatments, with or without abdominal belt, increased ventilation to anterior lungs regions, compared to the left-lateral and right-lateral positions. Global ventilation 3 hours after IPPB treatments remained higher than at baseline and was best preserved with the use of an abdominal belt.

Application of histamine or serotonin to the hypoglossal nucleus increases genioglossus muscle activity across the wake-sleep cycle.

The decrease in genioglossus (GG) muscle activity during sleep, especially rapid eye movement (REM) or paradoxical sleep, can lead to airway occlusion and obstructive sleep apnoea (OSA). The hypoglossal nucleus innervating the GG muscle is under the control of serotonergic, noradrenergic and histaminergic neurons that cease firing during paradoxical sleep. The objectives of this study were to determine the effect on GG muscle activity during different wake-sleep states of the microdialysis application of serotonin, histamine (HA) or noradrenaline (NE) to the hypoglossal nucleus in freely moving cats. Six adult cats were implanted with electroencephalogram, electro-oculogram and neck electromyogram electrodes to record wake-sleep states and with GG muscle and diaphragm electrodes to record respiratory muscle activity. Microdialysis probes were inserted into the hypoglossal nucleus for monoamine application. Changes in GG muscle activity were assessed by power spectrum analysis. In the baseline conditions, tonic GG muscle activity decreased progressively and significantly from wakefulness to slow-wave sleep and even further during slow-wave sleep with ponto-geniculo-occipital waves and paradoxical sleep. Application of serotonin or HA significantly increased GG muscle activity during the wake-sleep states when compared with controls. By contrast, NE had no excitatory effect. Our results indicate that both serotonin and HA have a potent excitatory action on GG muscle activity, suggesting multiple aminergic control of upper airway muscle activity during the wake-sleep cycle. These data might help in the development of pharmacological approaches for the treatment of OSA.

Sleep and respiratory function after withdrawal of noninvasive ventilation in patients with chronic respiratory failure.

BACKGROUND: In patients with restrictive thoracic disease, little is known about changes in sleep and breathing if the patient stops using nocturnal noninvasive ventilation (NIV). Better understanding of those changes may affect NIV management and improve our understanding of the relationship of night-to-night variability of respiratory and sleep variables and morning gas exchange. METHODS: With 6 stable patients with restrictive chronic respiratory failure who were being treated with home NIV we conducted a 5-step study: (1) The subject underwent an in-hospital baseline sleep study while on NIV, then next-morning pulmonary function tests. (2) At home, on consecutive nights, the subject underwent the same sleep-study measurements while not using NIV, until the patient had what we defined as respiratory decompensation (oxygen saturation measured via pulse oximetry [S(pO(2))] < 88% or end-tidal CO(2) pressure [P(ETCO(2))] > 50 mm Hg, with or without headaches, fatigue, or worsening dyspnea). Each morning after each home sleep-study night off NIV, we also measured S(pO(2)) and P(ETCO(2)). (3) The patient returned to the hospital for a second overnight assessment, the same as the baseline assessment except without NIV. (4) The patient went home and restarted using NIV with his or her pre-study NIV settings. (5) After the number of nights back on home NIV matched the number of nights the patient had been off NIV, the patient returned to the hospital for a third in-hospital assessment. We measured static lung volumes, maximum inspiratory and expiratory static mouth pressure, breathing pattern, arterial blood gases, S(pO(2)), P(ETCO(2)), and full overnight polysomnography values. RESULTS: Respiratory decompensation occurred 4-15 days after NIV discontinuation (mean 6.8 d). On the first and second in-hospital assessment nights, respectively, the mean nadir nocturnal S(pO(2)) values were 84 +/- 2% and 64 +/- 4%, the total apnea-hypopnea index values were 0 +/- 0 and 9 +/- 2, and the obstructive hypopnea index values were 0 +/- 0 and 7 +/- 1 episodes per total sleep hour. Respiratory events started on the first night off NIV. Spirometry, muscle strength, and sleep architecture did not change significantly. With resumption of NIV, baseline conditions were recovered. CONCLUSIONS: NIV discontinuation in patients with restrictive chronic respiratory failure previously stabilized on NIV promptly leads to nocturnal respiratory failure and within days to diurnal respiratory failure. Stopping NIV for more than a day or two is not recommended.

Prevalence of papilloedema in patients with sleep apnoea syndrome: a prospective study.

The association of papilloedema (PO) with respiratory diseases and especially obstructive sleep apnoea (OSA) syndrome has been emphasised in many reports. The pathophysiology could rely on the episodic increase of intracranial pressure related to apnoeic episodes during night sleep. Nevertheless, prevalence of papilloedema in patient with OSA syndrome remains unknown. As this information could improve diagnosis and therapeutic strategies, the aim of the present study was to investigate the prevalence of PO in an OSA syndrome population. From 95 successive, recently diagnosed OSA patients, 35 answered a questionnaire about visual symptoms and underwent fundoscopic examination. Visual symptoms suggestive of PO were present in 40% of the patients, but none had PO. As a conclusion, PO does not seem to be frequently associated with OSA syndrome and systematic screening of PO in these patients does not seem to be warranted. Nevertheless, patients with visual complaints evocative of papilloedema should have their eye fundus checked since the association between OSA and PO exists. Further studies, including more patients, might be useful to establish which patients are at particular risk for this complication.